When the suspension on your car is worn out, you may experience bouncing throughout your vehicle that your shocks and struts are supposed to absorb. Your tires also experience this bouncing, and in fact lose momentary contact with the ground. When they land, the compression and force scrapes away divots in your tires’ tread. Left unaddressed, these continuous impacts erode your tires in random patterns called cupping, or scalloping.
Causes of Tire Cupping
Cupping can also be caused by other worn out components, improper alignment, lack of tire maintenance such as regular tire rotations and/or hard cornering. The damage can become plainly visible to anyone who casually inspects their tires. It will look like bald spots in the rubber either in the middle or the edge of the tread.
Middle tread cupping is a sign of failed suspension component. However, under-inflation of your tires can also cause the formation of numerous small scallops. Edge cupping is also a sign of damage to your vehicle’s suspension components. Control arm bushings, ball joints, sway bar links, steering arm—they’re all essential to a smooth ride. Your tires can only dampen so much of the road.
Signs of Tire Cupping
In addition to feeling the bouncy effect of your car lacking solid suspension, you may also experience a low vibration in your vehicle. This is from driving on tires that essentially are uneven. The faster you drive, the higher the frequency of the vibration. Any of the above signs should warn you to immediately seek repairs and inspect your tires.
If you catch a problem with your suspension right away, there may be nothing wrong with your tires. But once cupping appears, many miles have most likely been shaved from their tread life.
Rotating the tires may allow you to smooth out the wear on them. Just know that it’s impossible to only lose tread from the highest points of your tire’s tread. The entire face of the tread will wear with use, and in time those cupped patches will erode ever thinner until a tire becomes worn to its legal limit prematurely.
So if you experience any unnatural motion in your vehicle, from bouncing to vibration or knocking—don’t think that it’s merely a mechanical problem. Making repairs in a timely manner may extend the life of your tires.